US10921497B2ActiveUtilityA9
Prism film, backlight module and display device
Est. expiryMar 29, 2038(~11.7 yrs left)· nominal 20-yr term from priority
G02B 6/0053G02B 5/045G02F 1/133607G02F 1/133611G02B 26/0891G02B 3/08G02F 1/133606G02B 30/33G02B 30/40G02F 2001/133607
55
PatentIndex Score
0
Cited by
18
References
17
Claims
Abstract
Embodiments of the present disclosure relate to a prism film, a backlight module, and a display device. The prism film includes a substrate and a plurality of prisms on a surface of the substrate, each of the plurality of prisms having a triangular cross section, and having a first optical surface, a second optical surface, and a third optical surface that are perpendicular to the triangular cross section, wherein the first optical surface is parallel to the surface of the substrate, the first optical surface and the second optical surface form a first bottom angle, the first optical surface and the third optical surface form a second bottom angle, and at least one of the first bottom angle and the second bottom angle of the plurality of prisms gradually changes.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A prism film comprising a substrate and a plurality of prisms on a surface of the substrate, each of the plurality of prisms having a triangular cross section and having a first optical surface, a second optical surface, and a third optical surface that are perpendicular to the triangular cross section,
wherein the first optical surface is parallel to the surface of the substrate, wherein the first optical surface and the second optical surface form a first bottom angle,
wherein the first optical surface and the third optical surface form a second bottom angle,
wherein at least one of the first bottom angle and the second bottom angle of the plurality of prisms gradually changes in a direction parallel to the surface of the substrate,
wherein the plurality of prisms are arranged in parallel in a direction parallel to the surface of the substrate,
wherein the first bottom angle and the second bottom angle are configured such that light entering the prism from the second optical surface is reflected toward the first optical surface by the third optical surface, and then emerges from the first optical surface by being deflected toward a center of the substrate,
wherein the direction is a direction of a horizontal component of the light parallel to the surface of the substrate,
wherein the at least one of the first bottom angle and the second bottom angle of the plurality of prisms gradually increases in the direction, and
wherein the first bottom angle and the second bottom angle are configured to satisfy the following relationship:
sin
θ
8
=
n
*
sin
[
α1
+
2
*
α3
-
π
+
arcsin
sin
(
θ1
-
α1
)
n
]
arcsin
sin
(
θ1
-
α
1
)
n
>
π
2
-
α1
-
α3
wherein θ1 represents an angle, facing the substrate, between a direction of light incident on the prism and a normal to a surface of the substrate, n represents a refractive index of the prism, al represents the first bottom angle, α3 indicates the second bottom angle, and θ8 represents an outgoing angle of light emerging from the first optical surface.
2. The prism film according to claim 1 , wherein the first bottom angle and the second bottom angle are configured such that the light incident to the third optical surface is totally reflected at the third optical surface, and wherein the first bottom angle and the second bottom angle are further configured to satisfy the following relationship:
θ5
=
π
-
α1
-
α3
-
arcsin
sin
(
θ1
-
α1
)
n
>
arcsin
1
n
wherein θ5 represents an incident angle of the light at the third optical surface.
3. The prism film according to claim 2 , wherein the triangular cross section is an isosceles triangular cross section.
4. The prism film according to claim 1 , wherein 65°≤θ1≤85°.
5. A backlight module comprising a light guide plate and a prism film on a light outgoing side of the light guide plate according to claim 1 .
6. The backlight module according to claim 5 , wherein a side of the prism film provided with the prisms is opposite to a light outgoing side of the light guide plate, and wherein an outgoing angle of light emerging from the light guide plate ranges from about 65° to about 85°.
7. A display device comprising a prism film according to claim 1 .
8. The display device according to claim 7 , further comprising a backlight module and a display panel, wherein the prism film is located between a light guide plate of the backlight module and the display panel, wherein a side of the prism film provided with the prisms is opposite to a light outgoing side of the light guide plate, and wherein an outgoing angle of light emerging from the light guide plate ranges from about 65° to about 85°.
9. The display device according to claim 7 , wherein the display device is a virtual reality display device.
10. A prism film comprising a substrate and a plurality of prisms on a surface of the substrate, each of the plurality of prisms having a triangular cross section and having a first optical surface, a second optical surface, and a third optical surface that are perpendicular to the triangular cross section,
wherein the first optical surface is parallel to the surface of the substrate,
wherein the first optical surface and the second optical surface form a first bottom angle,
wherein the first optical surface and the third optical surface form a second bottom angle,
wherein at least one of the first bottom angle and the second bottom angle of the plurality of prisms gradually changes in a direction parallel to the surface of the substrate,
wherein the second bottom angle is a right angle,
wherein the first bottom angle is configured such that light entering the prism from the first optical surface is directly incident on the second optical surface, and then emerges from the second optical surface by being deflected toward the center of the substrate,
wherein the first bottom angle of the plurality of prisms gradually decreases from an edge of the substrate toward the center of the substrate, and
wherein the first bottom angle is configured to satisfy the following relationship:
δ
=
arcsin
[
n
*
sin
(
α1
+
arcsin
sin
β1
n
)
]
-
α
1
α1
+
arcsin
sin
β1
n
<
arcsin
1
n
wherein δ represents an angle between light emerging from the second optical surface and a normal to the first optical surface, n represents a refractive index of the prism, prism, α1 represents the first bottom angle, and β1 represents an incident angle of the light at the first optical surface.
11. The prism film according to claim 10 , wherein 0°≤β1≤20°.
12. The prism film according to claim 10 , wherein the plurality of prisms are arranged in parallel in a direction parallel to the surface of the substrate.
13. The prism film according to claim 10 , wherein the plurality of prisms are arranged in a form of a plurality of concentric circles.
14. A backlight module comprising a light guide plate and a prism film on a light outgoing side of the light guide plate according to claim 10 .
15. The backlight module according to claim 14 , wherein a side of the prism film provided with the prisms faces away from a light outgoing side of the light guide plate, and wherein an outgoing angle of the light emerging from the light guide plate ranges from about 0° to about 20°.
16. A display device comprising a prism film according to claim 10 .
17. The display device according to claim 16 , further comprising a display panel, wherein the prism film is located on a light outgoing side of the display panel, wherein a side of the prism film provided with the prisms faces away from a light outgoing side of the display panel, and wherein an outgoing angle of the light emerging from the light guide plate ranges from about 0° to about 20°.Cited by (0)
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